W202 96 mot failure

[Maxwell]

Advise needed please
Mot failed on rear exhaust emission CO cotent at idle excessive after 2nd fast idle and hydrocarbon content see test result
Fast Idle
CO - 0.617 Lambda 1.055

2nd Fast Idle Test
CO - 0.591 Lambda 1.054

Natural Idle Test
CO 0.572

The car was tested at 3:30pm from parking the night before
The garage says i need my CAT converter change Not too sure of this garage
Advisory items it say both front wipers in poor condition but i only have one
Am so confused Help help

 

[Supacool1]

Did they let the car fully warm up and do the testing after it had been driven? Sometimes this yeilds different figures as the cat chemicals warm up and work better...?

 

[SilverSaloon]

Put some injector cleaner in the fuel tank and take it for an "italian tuneup" (do a search). Get it nice and hot and return it for a retest, or take it elsewhere.

 

[bennesspipers]

They usually rev the nuts off most cars to get them up to full working temp, were you there when they did the test ?

 

[Maxwell]

I wasnt there when they did the test

 

[NICKYB]

The mrs mini one failed on this last week, The garage added some injector cleaner then reved the nuts of it got it up to temp and it flew through!

 

[stevesey]

They usually rev the nuts off most cars to get them up to full working temp, were you there when they did the test ?

Yep - mine was iddling for most of the test (on Friday) and was at 0.28 to start as the CATs has cooled off. Had to give a good blast of revs, then all of a sudden the CO dropped as theCAT got up to a working temp.

Has a rev like this this for the past three years - said to the tester that next year we'll have to do the emissions test first.

Lamda and HCs on mine was 1.01 and 74ppm, your Lamda is high and if the HCs where high as well - it might be something other than the CAT anyway - or just not warmed up at all.

 

[Ted]

+1 for an italian tune up.

 

[NW_Merc]

do forte do injector cleaner?

 

[cammy]

Forte do an injector cleaner.
http://www.forteuk.co.uk/product.php

 

[nadeem]

Same problem with my e320 and e320 cdi, just wouldn't pass until I used cataclean and Italian tune up. Sometimes the cats become blocked and need the extra pressure to blow the junk out.

Oh check for exhaust leaks before and after the o2 sensors, as my e430 failed 7 times until the garage decided to check the exhaust system and guess what leaking from the exhaust manifold.

 

[bouncer]

Lambda is too high = AIR LEAK
Too much oxygen at tailpipe reading.

as above check exhaust for leaks and holes, check joints for black carbon stains. You may not hear it blowing but even the smallest leak will affect the emissions.

sTeVe